Veronica Roth is having the kind of year most authors can only dream of. In addition to her debut novel, "Divergent," going into production with rising stars Shailene Woodley and Theo James cast as leads, Roth is wrapping up the trilogy that captured the publishing (and film) industry's attention with Tuesday's publication of "Allegiant."

Set in a near-future Chicago, the "Divergent" series tells the story of a civilization divided into five factions, each representing a different virtue: Abnegation (selflessness), Erudite (intelligence), Dauntless (bravery), Amity (peacefulness) and Candor (honesty). Teens are tested at 16 years old to determine which faction they will call their own. Our protagonist here is Beatrice "Tris" Prior, who leaves her Abnegation family to join up with the dangerous Dauntless — despite receiving inconclusive test results. In Tris' world, to be different is to be dangerous, and there are many who will try to take her down.

Following a cliff-hanger ending in Roth's second novel, "Insurgent," fans have been not-so-patiently waiting to learn the fate of Tris and her hunky love interest Four (otherwise known as Tobias). And with "Allegiant" now in readers' hot little hands, Roth is feeling all kinds of things.

"It's a really huge mix of emotions," she told MTV News' Josh Horowitz on publication day. "I'm nervous. I'm like, how are people going to react to this? I'm also really excited, but it's also really bittersweet to close out the trilogy. It's been a couple years of my life. It's been a huge part of my life and changed everything, and to have it finish is like, oh, I have to let these characters go now. It's a little sad."

Fans will no doubt notice something new in this final installment. Unlike "Divergent" and "Insurgent" before it, this book is told from two points of view: Tris' and Tobias'.

"I didn't really want to do the dual perspectives," Roth admitted. "I really just wanted to stick with Tris through the whole thing and make it consistent. But as I started writing it, I realized I was losing large parts of the story by not having someone else's perspective. The really useful thing about it is, something will happen and Tris will react to it in a particular way, and she's a little judgmental. She kind of jumps to conclusions sometimes, and now we have Tobias reacting to the same situation in the opposite way or a slightly different way, so it was very interesting and really useful to be able to show the same things from different angles. You kind of have to say, 'Who do I think is right about this, or is the truth somewhere in the middle?' Those are interesting things for me as a writer."

Another issue to contend with: not picturing Woodley and James as her lead characters while wrapping up the final novel.

"It got a little tricky while editing," Roth said. "Luckily, I finished most of the heavy revising before they cast anything. I was really determined to finish before it got too far because I didn't want them to take over. I love everyone who was cast, but sometimes they're not the exact description, like wrong hair color or whatever, and so I don't really want to start imagining them because I'll mess up. I mostly kept my images in mind, but if I re-read, Theo and Shailene are creeping into my brain, which is kind of creepy because they're making out, and I'm like, 'Nooooo! Sorry, I did that to you!' "

"Allegiant" is on bookstore shelves now, while "Divergent" will hit theaters March 21, 2014.